Geometrical instrument.



M. E. FERNALD.

GEOMETRICAL INSTRUMENT.

APPLICATION FILED MAR. 22, 1915.

1,284,881., Patented NOV. 12, 1918.

3 SHEETSSHEET I.

M. E. FERNALD.

GEOMETRICAL INSTRUMENT.

APPLICATION FILED MAR. 22. ms.

11 28%,881 o Patented Nm'. 12, 1918.

3 SHEETSSHEET 2 mmmws, firm/0r, .m m M W TM M. E. FERNALD.

GEOMETRICAL INSTRUMENT.

APPLICATION FILED MAR. 22, 1915.

1 ,28%,881 Patented Nov. 12, 1918.

3 SHEETSSHEET 3.

MARK E. FERNALD, OF SAUGUS, MASSACHUSETTS.

GEOMETBICAL INSTRUMENT.

Specification of Letters Patent.

Patented Nov. 12, 19118.

Application filed March 22, 1915. Serial No. 16,049.

To all whom it may concern:

Be it known that I, MARK E. EEnNALD, a citizen of the United States,residing at Saugus, in the county of Essex and State of Massachusetts,have invented a" new and useful Improvement in Geometrical Instruments,of which the followlng 1s a specification.

The present invention relates to geometrical instruments and moreparticularly to instruments for use in the manufacture of castingpatterns.

It has been proposed to perform the various operations in themanufacture of shoes automatically. In one system of automatic shoemachines the transfer'of the point of operation of the tool along thework is controlled by a leader upon which the Work supporting jacket ismounted, These leaders usually comprise a body portion having the samearea on one face as the projected area of the sole of the shoe mountedupon the jack and a fian ge on the edge of the body portion whlch isusually provided with teeth for engagement with a driving pinion. Theflange also acts as a guide for swinging the ack laterally to permit thetool to traverse the reverse curves of the Work. One of the principal obections to theme of these/automatic machines is the cost of producingthe leaders which varv in size and shape with the various sizes andstyles of soles intended to be incorporated into a shoe. As well knownto those skilled in the art it 1s necessary in making a casting patternto allow for the shrinkage in the casting. Furthermore, in making aleader for a shoe mach ne it is also necessary to allow for the springof the last upon which the sole to be 1I1COIpO- rated into the shoe issecured. The principal reason for the high cost .of these leaders isthat heretofore it has been necessary to employ a skilled pattern makerin order to produce a sole-shaped blank having the metal shrinkage andthe spring of the last measurements incorporated therein. I haveconceived the idea of mechanically making casting patterns thuseliminating the need of a pattern maker and thereby making a system ofautomatic machines an economical factor in the manufacture of shoes.

The object of the present invention is to produce an instrument whichwill accurately plot a blank for a casting pattern havlng either themetal shrinkage measurement or the spring of the last measurement, orboth the metal shrinkage and the spring of the last measurementsincorporated therein.

To the accomplishment of this object a feature of the present inventioncontemplates the provision in a geometrical instrument of a form and atracer engaged therewith relatively movable to transfer the point ofengagement of the tracer around the form, and a recorder for recordingthe relative movement of the form and tracer plus an increment theamount of which is predetermined from a table of metal shrinkage. Theform may be the casting or merely have the dimensions of the casting. Inthe specific embodiment of the invention the form is preferably the soleon a last. The recorder may have any suitable mechanical embodimentfound desirable or expedient. It is preferred, however, to employ ascriber for indicating or delineating the measurements of the blank forthe casting pattern.

Another feature of the present invention contemplates the provision in ageometrical instrument of a support for'a shoe last and a tracerarranged to engage the margin of a sole positioned on the lastrelatively movable to transfer the point of engagement of the traceraround the sole and generate an area equal to the projected area of thesole on the last. With this construction the spring of the lastmeasurement may be ac curately determined. Broadly considered inaccordance with the object of the invention this last named feature maybe employed alone or combined with the first named feature so that asole-shaped area may be recorded or generated having the metal shrinkageand the spring of the last measurements incorporated therein.

Other features of the invention relate to certain devices, combinationsand arrangements of parts hereinafter described and then set forthbroadly and in detail in the appended claims which possess advantagesreadily apparent to those skilled in the art.

The various features of the present in-' tracer.

v Describing now in general terms my novel method of makingcastingpatterns which determine the form of the leaders employed inautomatic shoe machines, the first step consists in the production ofthe blank for the foundation of the pattern. As well known to thoseskilled in the art it is necessary in making a casting pattern to allowfor the shrinkage in the casting. Furthermore, in making a leader for ashoe machine it is necessary to allow for the spring of the last uponwhich the sole to be incorporated into-a shoe is .secured. To produce asoleshaped blank having the metal shrinkage and the spring of the lastmeasurements incorporated therein, I mount the sole upon a last andcause a traceroperatively connected to a recorder, such as a scriber, totravel around the margin of the sole on the last. The tracer is mountedto generate a soleshaped area equal to the projected area of the soleand the movement of the tracer in generating this area is transmitted tothe scriber. Interposed in the connections between the tracer and thescriber is a differential mechanism which enlarges, by the amount of themetal shrinkage, the move-' ment imparted to the scriber-by the tracer.By this means a sole-shaped area is traced having the metal shrinkageand the spring of the last measurements incorporated therein. With thissole-shaped area as a guide a flat blank is made having the same sizeand shape. This sole-shaped blank is then inserted into the machinedisclosed in application Serial No. 868,921, filed by me October 27,1914. This machine is provided with a rotatable support for the blank,devices for supporting, guiding and feeding a strip of material, such aspaper, and a pair of rolls for attaching the paper to the peripheraledge of the blank and winding the paper in layers thereon to build theguiding flange. After the pattern is completed by this machine the draftnecessary for the removal of the pattern from the sand is imparted tothe pattern by a second machine which is disclosed in application SerialNo. 869,336, filed by Charles C. Blake, October 29, 1914, to whichreference is made by permission. This machine is provided with a seriesof rolls which simultaneously support, guide, feed and operateautomatically upon the pat 1,2e4,es1

tern to impart the draft thereto and remove any roughness on the topand. bottom faces of the flange. The pattern is then provided with acoat of oil or shellac.

r In the illustrated embodiment of the invention a sole 1 (Figs. 2 and4) is secured to the bottom of a last 2 which is jacked upon a spindle 3and a saddle 4 carried by the frame of the instrument.

In order to generate an area equal to the pro]ected area of the sole onthe last, which is the area bounded by perpendiculars dropped from theedge of the sole to a plane, the margin of the sole is engaged by atracer 6 (Figs. 4 and 6). The tracer comprises a frusto-conical roll 7mounted to engage the face of the sole and a cylindrical roll 8 mountedto engage the edge of the sole.

The roll 7 is mounted to rotate about an axis substantially parallel tothe face of the sole 1 upon a stud 9 secured to a carrier 10 for thetracer. The roll 8 is mounted to rotate about an axis substantiallyparallel to the edge of the sole on a race 11 which rotates on a collar12 carried by a stud 13 on the carrier 10. To transfer the point ofengagement of the tracer around the sole on the last the carrier 10carries a handle 14 which is rotatably mounted on a race 15 carried by acollar 16 secured to the carrier 10.

In order that the tracer may adapt itself automatically to the slope ofthe sole and to the reverse curvatures along its periphery the carrier10 is loosely suspended by a cap 17 in a pair of races 18 which aremounted in boxes 19 formed in a support or truck 20 'a series of wheels21 arranged to roll upon the top and bottom edges of a rail 22. .Themovement of the truck 20 on the rail 22 is limited in both directions bypins 22.

To permit the tracer to move laterally of the sole the rail 22 ismounted on a base 23 (Fig. 5) which is pivotally mounted on a post 24(Fig. 5) carried by the frame of the instrument. To'this end the base 23is provided with a central conical bearing 24 arranged to engage aconical tip 25 On the post and a depending tube 26 which rotates on arace 27 carried by a collar 28 on the post.

With this construction the tracer may be engaged with the margin of thesole and transferred around the sole while engaged therewith. When thepoint of engagement of the tracer is transferred around the sole thecarrier 10 automatically rotates to main tain the rolls 7 and 8 in theirproper relation to the margin of the sole as the tracer travels alongthe reverse curvatures of the sole. The carrier 10 also rises and fallsto accommodate the tracer to the slope of the sole. Durin the transferof the point of engagement o the tracer around the sole the truck 20rolls along the rail 22 thus permitting the tracer to be transferredlongitudinally of the sole and the base 23 turns on its pivot to permitthe tracer to be transferred laterally of the sole.

In order to .record the movement of the tracer as it is transferredaround the sole a rail 29 (Fig. 3) similar to the rail 22 carries asecond truck 30 similar in construction to the truck 20. This truck 30loosely carries a pencil or scriber 31 arranged to travel over a sheetof paper 32 (Fig. 1) removably secured to a board 33 the surface ofwhich is arranged in a horizontal plane.

In order to transmit the movement of the tracer to the scriber the truck20 is connected to a rack 34 which is guided and supported by threesmall rolls 35 (Fig. 4) and a large roll 36 (Fig. 5) which are mountedin a guideway 37 depending from the rail 22. The rack 34 meshes with agear 38 (Fig. 5) which is rotatably' mounted on a post 39 carried by thebase 23 and arran ed concentric to its axis. The gear 38 is pinned to asecond gear 40 which meshes with a second rack 41 (Figs. 1, 3 and 5).The rack 41 is guided and. supported by three small rolls 42 (Figs. 3and 4) and a large roll 43 (Fig. 5) which are carried by a guideway 44depending from the rail 29. The rack 41 is connected to the truck 30.

With this construction all the movements of the tracer, except itsvertical and pivotal movements, are transmitted to thescriber. As thevertical and pivotal movements of thetracer are provided merely for thepurpose of maintaining the tracer in proper relation to the margin ofthe sole as its point of engagement is transferred around the sole allthe transferring movement of the tracer is transmitted to the scriber.As the rack 34 moves in all directions in a horizontal plane it isobvious that the tracer generates an area which is equal to theprojected area of the sole, that is, an area bounded by perpendicularsdropped from the edge of the sole to a plane.

From this construction so far described it is clear that if the gears 38and 40 are provided with the same number of teeth the scriber willdelineate upon the sheet of paper 32 an area equal to the area generatedby the tracer. In order, however, to enlarge the movement of the scriberresponsive to the movement of the tracer by an increment the amount ofwhich is predetermined from the known shrinkage of the metal of whichthe leader is to be made the gears 38- and 40 are provided withdiiferent numbers of teeth the ratio of which is calculated from thefollowing table Table of metal shrinkage.

Shrinkage Metal. loom Cast iron- Brass For instance, if the leader foruse in the automat1c shoe machine were made ofcast 1ron the table ofmetal shrinkage would be consulted where it would be found that cast1ron shrlnks a inch per footand that the ratio of the teeth in the gearsshould be 96 to 97 in order to enlarge the movement of the scriber,responsive to the movement of the tracer, by an increment the amount ofWhlCl'l is inch per foot. In order there foreto plot a blank for apattern for use in making iron castings the gear 38 should have 96 teethand the gear 40 should have 97 teeth. While the primary object of thepresent invention is directed to a narrow field in the'art ofmetal-founding, I believe that I am the first to have conceived the ideafor the mechanical production 'of casting patterns and to have devisedoperative mechanlsm for carrying such idea into practice. -Consequently,the primary object of the present mvention is not to be understood aslimiting the scope of the claims, where the context otherwise permits,to an instrument for use in making patterns for casting lead-v ers forautomatic shoe machines as it will be its apparent to those skilled inthe art that an instrument having the features and combinations of partshereinbefore described is well adapted for general use in making castmgpatterns.

It will be apparent to those skilled in-the art that the table of metalshrinkage set forth herein'includes onl the metals and alloys generallyemployed in casting. In the event that some other metal or alloy were tobe used in casting, the shrinkage of said metal or alloy would first bedetermined and the ratio of the teeth of the gears 38 and 40 calculatedfrom the determined shrinkage. Obviously other metals or alloys may beadded to the table of metal shrinkage herein set forth without departingfrom the spirit of the invention. It will also be apparent that thetraveling scriber 31 may indicate directly upon the material, such aswood or cardboard, for the blank.

class of machines and withlthe general objects of the .present inventionin view, that changes may be madein the details of structure, thedescribed and illustrated embodiment thereof being intended as anexploitation of its underlying essentials the features whereof aredefinitely stated in their true scope in the claims herewith. v

What is claimed as new, is

1. A, geometrical instrument, having, in combination, a support for aform and a tracer engaged with the form relatively movable to transferthe point of engagement of the tracer around the form, and a recorderresponsive to the relative movement of the form and tracer for recdrdingsaid movement plus an increment the amount of which is predeterminedfrom a table of metal shrinkage, substantially as described.

2. A geometrical instrument, having, in combination, a support for aform and a tracer engaged with the form relatively movable to transferthe point of engagement ofthe tracer around the form, a recorderresponsive to the relative movement of the form and tracer, and meansfor amplifying the indication of the recorder by an increment the amountof which is predetermined from a table of metal shrinkage,

substantially as described.

3. A geometrical instrument, having, in combination, a support for ashoe last and a tracer, engaged with a sole positioned on the lastrelatively movable to transfer the point of engagement of the traceraround the sole on the last, and a scriber responsive to the relativemovement of the support and tracer arranged to record said movement plusan increment the amount of which is predetermined from a table of metalshrinkage, substantially as described.

4. A geometrical instrument, having, in combination, a support for ashoe last, a tracer, arranged to engage a sole positioned upon the last,movable to transfer the point of engagement of'the tracer around thesole, and a scriber responsive to the movement of the tracer arranged torecord said movement plus an increment the amount of whichispredetermined from a table of metal shrinkage, substantially asdescribed.

5. A geometrical instrument, having, in combination a support for a shoelast, a tracer, arranged to engage a sole positioned upon the last,movable to transfer the point 0 engagement of the tracer around thesole, a scriber arranged to respond to the movement of the tracer, andmeans for amplifying the movement of the scriber responsive to themovement of the tracer by an increment the amount of which ispredetermined from a table ofmetal shrinkage, substantially asdescribed.

6. A geometrical instrument, having, in

generate an area equal to the projected area of the sole on the last, arecor er responsive to the movement of the tracer, and means foramplifying the indication of the recorder by an increment the amount ofwhich is redetermined from a table of metal shrinkage, substantially asdescribed.

8. A geometrical instrument, having, in combination, a support for ashoe last, a tracer, arranged to engage the margin of a sole positionedupon the last, movable to generate an area' equal to the rojected areaof the sole on the last, a scri er responsive to the movement of thetracer, and means for amplifying the movement of the scriber responsiveto the movement of the tracer by an increment the amount of which ispredetermined from a table-of metal shrinkage, substantially asdescribed.

9. A geometrical instrument, having, in combination, a support for ashoe last, a tracer arranged to engage the margin of a sole positionedupon the last, said support and tracer being relatively movable in thedirection of the length and width of the last to transfer the point ofengagement of the tracer around the sole and also in the direction ofthe height of the last to accommodate for variations in the slopeof thesole, a scriber, and connections between the tracer and the scribeiconstructed and arranged to transmit to the scriber the relativelengthwise and widthwise movements of the support and tracer,substantially as described. 10. A geometrical instrument, having, incombination, a support for a shoe last, a tracer, arranged to engage themargin of a sole positioned upon the last, movable in the direction ofthe length and width of the last to transfer the point of engagement ofthe tracer around the sole and also in the direction of the height ofthe last to accommodate for variations in the slope of the sole, ascriber, and connections between the tracer and the scriber constructedand arranged to transmit to the scriber the lengthwise and widthwisemovements of the tracer, substantially as described.

11. A geometrical instrument, having, in combination, a support for aform and a tracer engaged with the form relatively movable to transferthe point of engagement of the tracer around the form, a

scriber, and a differential connection between the tracer and thescriber for enlarging the movement of the scriber responsive to therelative movement of the form and tracer by an increment the amount ofwhich is redetermined from a table of metal shrinkage, substantially asdescribed.

12. A geometrical instrument, having, in combination, a support for aform, a tracer arranged to engage the form and movable to transfer thepoint of engagement of the tracer around the form, a scriber, and adifferential connection between the tracer and the scriber comprising apair of gears having different numbers of teeth the ratio of which iscalculated from a table of metal shrinkage, substantially as described.

13.'A geometrical instrument, having, in combination, a support for aform, a tracer arranged to engage the form and movable to transfer thepoint of engagement of the tracer around the form, a rack connected tothe tracer, a gear engaged by the rack, a second gear having a differentnumber of teeth than the first gear arranged to rotate with the firstgear, a second rack engaged by the second gear, and a scriber connectedto the second rack, substantially as described.

14. A geometrical instrument, having, in combination, a support for aform, a tracer arranged to engage the form and movable to transfer thepoint of engagement of the tracer around the form, a scriber, andconnections between the tracer and scriber comprising a pair of rackslongitudinally movable and rotatable in a horizontal plane,substantially as described.

15. In a geometrical instrument, a tracer comprising a frusto-conicalroll arranged to engage the face of a form and a cylindrical rollarranged to engage the edge of the form, substantially as described.

16. A geometrical instrument, havin in combination, a tracer comprisinga re] ar ranged to en age the face of a form and a roll arrange toengage the edge of the form, and a carrier for the tracer mounted torotate about an axis substantially normal to the face of the form and toslide in the direction of extent of said axis, substantially asdescribed.

17 In a geometrical instrument, a support for a shoe last and a tracercomprising a pair of rolls arranged to engage respectively the face andedge of a sole positioned on the last and mounted to rotate about axessubstantially parallel to the respective engaged surfaces, substantiallyas described.

18. A geometrical instrument, having, in combination, a support for ashoe last, a tracer arranged to engage a sole positioned on the last, acarrier for the tracer mounted to rotate about an axis substantiallynormal to the face of the sole, to slide vertically, and to movelongitudinally and laterally of the sole on the last, substantially asdescribed.

19. A geometrical instrument, having, in combination, a support for aform, a tracer, arranged to engage the form movable to transfer thepoint of engagement of the tracer around the peripheral edge of the formand rotate about an axis coincident with said edge to adapt itself tothe varying curvatures of the form, and a handle for moving the traceraround the form, substantially as described.

20. A geometrical instrument, having, in combination, a support for aform, a tracer, arranged to engage the form, movable to transfer thepoint of engagement of the tracer around the form and mounted to rotateand slide vertically on its axis of rotation, and a handle for movingthe tracer around the form connected to move vertically with the tracer,substantially as described.

21. A geometrical instrument, having, in combinatlon, a support for alast having its bottom curved laterally and longitudinally, and meansfor projecting the edge of a sole secured to the bottom of the last upona plane, substantially as described.

K E. FERNALD.

